My bf has 40 guitars and teaches it to kids sometimes. He says in terms of playability, an electric is easier because the strings are closer to the fretboard. You don't have to press down so hard.
It's better to start with an acoustic because you can play it anywhere because you don't have to plug in the amp.
But to learn learn, it doesn't really matter, except you can't hear an electric without it being plugged in.
Also, the costs are more expensive for electric. A decent acoustic would be about $400.
He plays acoustic only, by the way. It's sort of like learning to drive a manual car then driving an automatic, or learning to dive in cold water then diving in warm.